1. Field of the Invention
The present invention relates to a road load simulation apparatus as a test bench for a motorcycle or the like, and particularly to a road simulation apparatus capable of simulating, in test bench conditions, a load proximate to that experienced by a motorcycle actually running on a road.
2. Background Art
For example, a conventional road simulation apparatus includes front excitation means capable of exciting a front axle of a motorcycle upwardly and downwardly as well as forwardly and rearwardly is connected to the front axle. Rear excitation means capable of exciting a rear axle upwardly and downwardly is connected to the rear axle so that a road load proximate to that experienced upon running of a motorcycle on an actual road can be regenerated based on operation of the excitation means (refer to the official gazette of Japanese Patent Laid-open No. Hei 5-149833).
However, in the conventional road simulation apparatus described above, parallel arms are provided which prevent the vehicle from falling down. The parallel arms are supported for upward and downward rocking movement by a stationary support member positioned rearwardly of the vehicle body. Front ends of the parallel arms are connected to a rear axle of the motorcycle to permit pivoting motion of the vehicle body.
In a structure as just described hereinabove, movements of the rear axle in the forward and rearward directions are restricted considerably by the parallel arms whose front ends are effectively limited to simple arcuate movements in the upward and downward directions upon vibrations of the rear axle upwardly and downwardly. Consequently, the stress sensitivity is increased at a portion which is subject to this restriction. This portion is therefore subject to more severe stress conditions than that experienced upon vehicle operation on an actual road. Accordingly, the reproduction performance of the road load may be deteriorated with this type of conventional structure.
The present invention overcomes the shortcomings associated with the prior art and achieves other advantages not realized by the prior art.
An object of the present invention is to solve the above-described problems of the prior art and to provide a road simulation apparatus with a simplified structure that can solve the problems of conventional road simulation apparatus.
An object of the present invention is to remove artificial restrictions and their associated stress concentrations on a vehicle body subjected to a road simulation apparatus under test conditions.
An object of the present invention is to enhance operational stability of a vehicle body subjected to test conditions according to the road simulation apparatus by preventing the vehicle body from falling over while maintaining accurate road simulation.
A further object of the present invention is to reduce interference between corresponding parts of the road simulation apparatus and vehicle body.
These and other objects are accomplished by a road simulation apparatus for a vehicle having front excitation means capable of exciting a front axle of said vehicle and rear excitation means capable of exciting a rear axle of said vehicle, wherein operation of said front and rear excitation means regenerates a test load representative of a road load experienced by said vehicle when running on an actual road, said road simulation apparatus comprising a bendable link mechanism including a plurality of links which are disposed in forward and rearward directions of said vehicle for permitting mutual bending motion therebetween and a one end portion connected for pivotal motion to a stationary support member, and an other end portion of said bendable link mechanism is connected for pivotal motion to a rear portion of a vehicle body of said vehicle such that movements of said vehicle body in said forward and rearward directions upon excitation of said front and rear excitation means is permitted while said vehicle body is simultaneously prevented from falling down by said bendable link mechanism.
These and other objects are further accomplished by a road simulation apparatus for a vehicle having front excitation means capable of exciting a front axle of said vehicle and rear excitation means capable of exciting a rear axle of said vehicle, wherein operation of said front and rear excitation means regenerates a test load representative of a road load experienced by said vehicle when running on an actual road, said road simulation apparatus comprising a falling down prevention mechanism including a front slide member connected for pivotal motion to a rear portion of a vehicle body at a connection portion and extending rearwardly farther than the connection portion, a rear slide member connected for pivotal motion to a stationary support member located on a rear side from said vehicle and extending forwardly farther than the connection portion, and a slide connection mechanism provided between the two slide members for connecting the two slide members for sliding movement in the forward and rearward directions of said vehicle body while inhibiting relative rotation of the two slide members upon excitation of said front and rear excitation means.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.